New potato micro-tuber-inducing cyclohexene compounds related to theobroxide from Lasiodiplodia theobromae

Two new cyclohexene compounds related to theobroxide (3) were isolated from the mycelia of Lasiodiplodia theobromae OCS71. The structures of these compounds were determined to be (4S,5S)-4,5-dihydroxy-2-methyl-cyclohex-2-enone (1) and (3aS,4R,5S,7aR)-4,5-dihydroxy-7-methyl-3a,4,5,7a-tetrahydrobenzo[1,3]dioxol-2-one (2) by means of spectroscopic analyses and chemical correlation to 3. Compound 2 was shown to take up the carbonate ion to form a carbonic acid ester nonenzymatically. The compounds also showed potato micro-tuber-inducing activities at a concentration of 10(-3) m, using a culture of single-node segments of potato stems in vitro.